title: The paradox of enrichment in phytoplankton by induced competitive interactions.
abstract: The biodiversity loss of phytoplankton with eutrophication has been reported in many aquatic ecosystems, e.g., water pollution and red tides. This phenomenon seems similar, but different from the paradox of enrichment via trophic interactions, e.g., predator-prey systems. We here propose the paradox of enrichment by induced competitive interactions using multiple contact process (a lattice Lotka-Volterra competition model). Simulation results demonstrate how eutrophication invokes more competitions in a competitive ecosystem resulting in the loss of phytoplankton diversity in ecological time. The paradox is enhanced under local interactions, indicating that the limited dispersal of phytoplankton reduces interspecific competition greatly. Thus, the paradox of enrichment appears when eutrophication destroys an ecosystem either by elevated interspecific competition within a trophic level and/or destabilization by trophic interactions. Unless eutrophication due to human activities is ceased, the world's aquatic ecosystems will be at risk.
authors.affiliation: 1] Graduate School of Science and Technology, Shizuoka University, 3-5-1 Johoku, Naka-ku, Hamamatsu, 432-8561, Japan [2] Mathematics Division, Institute of Mathematical Sciences and Physics, University of the Philippines Los Baños, College, Laguna 4031, Philippines.
authors.forename: Jerrold M
authors.initials: JM
authors.lastname: Tubay
authors.forename: Hiromu
authors.initials: H
authors.lastname: Ito
authors.forename: Takashi
authors.initials: T
authors.lastname: Uehara
authors.forename: Satoshi
authors.initials: S
authors.lastname: Kakishima
authors.forename: Satoru
authors.initials: S
authors.lastname: Morita
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Togashi
authors.forename: Kei-ichi
authors.initials: K
authors.lastname: Tainaka
authors.forename: Mohan P
authors.initials: MP
authors.lastname: Niraula
authors.forename: Beatriz E
authors.initials: BE
authors.lastname: Casareto
authors.forename: Yoshimi
authors.initials: Y
authors.lastname: Suzuki
authors.forename: Jin
authors.initials: J
authors.lastname: Yoshimura
mesh_terms: D000818:Animals; D044822:Biodiversity; D003198:Computer Simulation; D017753:Ecosystem; D005068:Eutrophication / Q000502:physiology*; D006801:Humans; D008954:Models, Biological; D010839:Phytoplankton; D011157:Population Dynamics; D011235:Predatory Behavior